Residential Flat Roof Insulation

The roof is only four years old so removing it is not an option he says ruling out a layer of exterior rigid foam.

Residential flat roof insulation.

Since your attic is insulated i would advise at least 2 of polyiso insulation in the roof for good measure. The target should be to achieve a u value of 0 25w m2k or better. Recommended roof insulation r value is 38 r but ideal is to have 50 r or more. The typical u value of an existing uninsulated flat roof is 1 5w m2k.

As for insulation thickness it depends on how much you can afford. That accounts for its materials membrane insulation and decking as well as snow and rainfall and even for equipment like an air conditioner. Rockwool stone wool roof insulation combines the thermal performance dimensional stability impact resistance and acoustic control required to increase the performance of many flat roof assemblies. Pros and cons for flat roof materials all three types of flat roofing cost 250 to 350 per square 100 square feet but prices vary according to region and size of the roof.

Different types of roofing insulation exist including blanket insulation blown insulation and rigid insulation. To achieve this add 100 to 160mm of insulation above the structural deck dependant upon insulant conductivity. With a flat roof however this becomes a major concern. Better to have 3 or more.

Thermafiber residential mineral wool blankets are ideal for insulating walls floor ceilings and attic spaces in homes. Underneath the basics flat roofs are usually constructed with a ceiling nailed to joists which support a deck usually wood in residential construction a vapor barrier insulation and a roof board. In climate zone 5 the prescriptive table of the international residential code requires at least r 49 of ceiling insulation. Products are also inorganic non combustible and mold resistant.

With 2 6 rafters that s a tall order and jordan adds a couple of major caveats. The type that is right for your flat roof insulation job depends upon the state of the roof expert opinion on the best type and your budget. Flat roofs usually come with a 10 to 20 year warranty but can last 25 years if you build the roofs right and maintain them using commonsense rules.